Magnetic head

ABSTRACT

A magnetic head includes a slider having any one of recording and reproducing elements, and a flexure having an elastically deformative tongue. The slider and the flexure are bonded together with a resin adhesive therebetween. The resin adhesive has a Young&#39;s modulus E in a range of 700 to 5,200 kg/cm 2  at 25° C. and a bond strength of 50 gf or more.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a floating type magnetic headdevice for use in a hard disk apparatus or the like. In particular, theinvention relates to a magnetic head in which a slider and a flexure forsupporting the slider are bonded together with an adhesive.

[0003] 2. Description of the Related Art

[0004]FIG. 3 is a partial side view of a known magnetic head device foruse in a hard disk apparatus.

[0005] The magnetic head device includes a slider 1 and a support 2 forsupporting the slider 1.

[0006] The slider 1 is composed of a ceramic material or the like. Athin-film element 4 is provided on the trailing end B, and the thin-filmelement 4 includes an MR head (read head) for reading magnetic signalsby detecting a leakage magnetic field from a recording medium such as ahard disk, using a magnetoresistance effect, and an inductive head(write head) in which a coil and so on are formed by patterning.

[0007] The support 2 includes a load beam 5 and a flexure 6.

[0008] The load beam 5 is composed of a leaf spring material such asstainless steel, and has a bent section 5 a having rigidity on each sideof the front portion. A predetermined elastic force can be displayed atthe base end of the load beam 5 in which the bent section 5 a is notformed.

[0009] A spherical pivot 7 which protrudes downward in the drawing isformed in the front portion of the load beam 5, and the slider 1 abutsagainst the pivot 7 with the flexure 6 therebetween.

[0010] The flexure 6 is composed of a leaf spring such as stainlesssteel. The flexure 6 includes a fixed section 6 a and a tongue 6 b, anda step 6 c connects the fixed section 6 a to the tongue 6 b.

[0011] As shown in FIG. 3, to the lower surface of the tongue 6 b, theslider 1 is bonded with a resin adhesive 20. An example of the resinadhesive 20 is a thermosetting epoxy resin adhesive.

[0012] A conductive pattern (not shown in the drawing) is provided onthe reverse side of the tongue 6 b, and an electrode terminal section(not shown in the drawing) formed of a thin film extracted from thethin-film element 4 is provided on the trailing end B of the slider 1.At the junction between the conductive pattern and the electrodeterminal section, a joint 9 is formed by ball bonding using gold (Au) orthe like. The joint 9 is covered with a reinforcing resin film 10 forprotection.

[0013] A fillet conductive resin film 21 is formed between the leadingend A of the slider 1 and the tongue 6 b. The conductive resin film 21is provided to secure electrical connection between the slider 1 and theflexure 6 and to dissipate static electricity to the support 2.

[0014] The upper surface of the tongue 6 b abuts against the pivot 7formed on the load beam 5, and the slider 1 bonded to the lower surfaceof the tongue 6 b can change the attitude freely, by means of elasticityof the tongue 6 b, with the apex of the pivot 7 serving as a fulcrum.

[0015] The slider 1 of the magnetic head device is applied force withthe elastic force of the base end of the load beam 5 in the direction ofthe disk D. The magnetic head device is used for a so-called “CSS”(Contact Start Stop) type hard disk apparatus or the like, and when thedisk D stops, an air bearing surface (flying surface) la comes intocontact with the recording surface of the disk D. When the disk Dstarts, an airflow occurs between the slider 1 and the surface of thedisk D along the disk movement, and the slider 1 is lifted by a shortspacing δ2 from the surface of the disk D because of a lifting forcecaused by the airflow.

[0016] When the slider 1 is lifted, as shown in FIG. 3, the leading endA of the slider 1 is lifted higher above the disk D than the trailingend B. While maintaining the lifting attitude, magnetic signals from thedisk are detected by the MR head of the thin-film element 4, or themagnetic signals are written by the inductive head.

[0017] In the conventional magnetic head device, however, the flatnessor crown height of the air bearing surface la of the slider 1 may easilychange, resulting in extreme difficulty in setting the spacing δ2 at agiven amount.

[0018] The flatness or crown height of the air bearing surface 1 a ofthe slider 1 easily changes because a rigid adhesive such as athermosetting epoxy resin adhesive is conventionally used as the resinadhesive 20 for bonding the upper surface of the slider 1 and the lowersurface of the tongue 6 b of the flexure 6 together.

[0019] As shown in FIG. 3, the trailing end B of the slider 1 is rigidlybonded to the tongue 6 b of the flexure 6 by the joint 9 formed by ballbonding.

[0020] Additionally, since the slider 1 has a coefficient of thermalexpansion which is different from that of the flexure 6, if the resinadhesive 20 bonding the upper surface of the slider 1 and the lowersurface of the tongue 6 b together is rigid, thermal stress owing to thedifference in coefficient of thermal expansion between the tongue 6 andthe slider 1 may affect the slider 1 with the resin adhesive 20therebetween, resulting in adhesive deformation with respect to theslider 1.

[0021] Generally, since the flexure 6 has a larger coefficient ofthermal expansion in comparison with the slider 1, for example, in thelow temperature region, the air bearing surface 1 a of the slider 1 isdeformed to be convex in relation to the disk D, and thus a spacing lossincreases, resulting in a decrease in output.

[0022] In the high temperature region, the air bearing surface 1 a ofthe slider 1 is deformed to be concave in relation to the disk D, andthus it is highly possible that the trailing end B of the slider 1collides with the surface of the disk D, and the minimum flying height(spacing amount) cannot be guaranteed.

[0023] Also, as shown in FIG. 3, when the conductive resin film 21 isprovided between the leading end A of the slider 1 and the tongue 6 b ofthe flexure 6, if the conductive resin film 21 is rigid the same as theresin adhesive 20, both the trailing end B and the leading end A of theslider 1 are rigidly bonded, resulting in larger adhesive deformationwith respect to the slider 1 owing to thermal stress.

SUMMARY OF THE INVENTION

[0024] The present invention has been achieved in order to overcome thedifficulties noted above with respect to the conventional art. It is anobject of the present invention to provide a magnetic head which canreduce adhesive deformation with respect to a slider by using a resinadhesive which is flexible particularly after curing in order to bondthe slider and a flexure together.

[0025] In accordance with the present invention, a magnetic headincludes a slider having an element for recording and/or reproducing anda flexure having an elastically deformative tongue. The slider and theflexure are bonded together with a resin adhesive therebetween. Theresin adhesive has a Young's modulus E in the range of 700 to 5,200kg/cm² at 25° C. and a bond strength of 50 gf or more.

[0026] Preferably, the resin adhesive has a glass transition temperaturein the range of 4 to 70° C.

[0027] Also, preferably, the resin adhesive has a product {E·(Tg−25°C.)} obtained by multiplying the Young's modulus E at 25° C. by thetemperature obtained by subtracting 25° C. from the glass transitiontemperature Tg in the range of 7,000 to 234,000 kg·°C./cm².

[0028] Also, when a conductive resin film is formed between an end ofthe slider and the flexure as a countermeasure against staticelectricity, the conductive resin film used has the same properties asthose of the resin adhesive described above.

[0029] Although, in conventional art, wiring is directly connected to aslider in order to output signals from a thin-film element provided onthe slider or to input signals to the thin-film element, as the slideris miniaturized, use of a magnetic head, in which a conductive patternis formed on a flexure for bonding the slider and the conductive patternand a conductive terminal section provided on the slider are bondedtogether with a ball bonding technique, has been implemented.

[0030] However, since one end (trailing end) of the slider is rigidlybonded to the flexure with a gold bump by ball bonding, if a resinadhesive used for connecting the slider and the flexure is rigid,adhesive deformation may easily occur in which the flatness or crownheight of the air bearing surface (flying surface) changes afterbonding.

[0031] Therefore, a flexible resin adhesive which can absorb strainowing to the difference in coefficient of thermal expansion between theslider and the flexure and which can decrease internal stress resultingfrom curing shrinkage is required as the resin adhesive used for bondingthe slider and the flexure.

[0032] For example, the resin adhesive may contain a thermoplastic resinsuch as an acrylic resin, a polyurethane resin, a polyester resin, or anylon resin as a major constituent, or may contain a thermosetting resinif it has elasticity in the operating temperature region.

[0033] The factors that determine flexibility of a resin adhesive (aftercuring) are the Young's modulus E and the glass transition temperatureTg of the resin adhesive.

[0034] When the glass transition temperature Tg of the resin adhesive ishigher than the operating temperature T and the resin adhesive isassumed to be an elastic body (having a Young's modulus E), a thermalstress δ caused by the resin adhesive to the slider (and the flexure) isrepresented by the following equation 1:

δ=E·ε=∫E(T)·Δα·(Tg−T)dT  Equation 1

[0035] (wherein Tg>T)

[0036] where ε is a strain between the slider and the flexure, and Δα isa difference in coefficient of thermal expansion between the slider andthe flexure.

[0037] In reality, since the resin adhesive (after curing) is aviscoelastic body, a portion of the strain ε between the slider and theflexure is absorbed (buffered) by viscous deformation and does notcontribute to adhesive deformation.

[0038] The adhesive deformation of the slider is considered to have apositive linear relationship with thermal stress δ. Therefore, at anoperating temperature T, as the Young's modulus E of the resin adhesiveincreases and as the glass transition temperature Tg increases, thermalstress δ increases and adhesive deformation increases.

[0039] When the glass transition temperature Tg of the resin adhesive islower than the operating temperature T, the Young's modulus of theadhesive decreases, and the resin adhesive has rubber elasticity.Therefore, even if a strain ε occurs between the slider and the flexure,the strain ε is absorbed by deformation of the adhesive, and thus,thermal stress δ that causes adhesive deformation does not show greateffects between the slider and the flexure.

[0040] The present inventors measured adhesive deformation of the sliderusing a plurality of resin adhesives having different properties forbonding the slider and the flexure together.

[0041] In experimentation, resin adhesive sample Nos. 1 through 10 shownin Table 1 were applied to joining surfaces of the slider and theflexure, and the resin adhesives were cured at 120° C. to bond theslider and the flexure together.

[0042] Also, a gold bump was formed between the trailing end of theslider and the flexure, and in order to protect the bump, the bump wascovered with a resin film.

[0043] The Young's modulus E of the resin adhesive was measured at 25°C. in accordance with a tensile test method (stress/displacement curve).The glass transition temperature Tg of the resin adhesive was measuredin accordance with a thermal mechanical analysis (TMA), and the adhesivedeformation of the slider was measured by a WYCO flatness meter. Bondstrength was measured by a peel test in which, using a slider and aflexure bonded to each other with a resin adhesive, the flexure waspulled perpendicular to the bond plane between the slider and theflexure. TABLE 1 Young's Glass modulus E transition Adhesive deformationBond strength (25° C.) temperature (Crown height) (nm) (gf) Sample No.Adhesive (kg/cm²) Tg (° C.) 5° C. 25° C. 50° C. 25° C. 50° C. 1 Epoxy5,000 34 2.0 0.4 0.1 87 80 2 Epoxy 13,500 132 28.0 27.4 21.0 51 88 3Adhesive 400 28 1.5 0.4 0.1 30 10 4 Adhesive 700 35 1.1 0.4 0.1 75 60 5Adhesive 1,000 4 1.7 0.7 0.1 70 55 6 Adhesive 3,000 69 1.8 1.3 0.5 71 707 Adhesive 3,500 20 1.7 0.8 0.2 80 62 8 Adhesive 5,200 70 3.0 2.0 0.7 8179 9 Adhesive 7,400 78 13.5 9.8 6.5 58 70 10 Cyanoacrylate 14,800 13023.1 22.8 17.4 75 98

[0044] A positive adhesive deformation shown in Table 1 indicates thatthe air bearing surface (flying surface) of the slider protrudes in thedirection of a disk, and a distance between the peak of the protrusionand the air bearing surface before deformation is defined as theadhesive deformation.

[0045] As shown in Table 1, sample Nos. 2, 9, and 10 have asignificantly higher adhesive deformation at 5° C., 25° C., and 50° C.in comparison with other samples.

[0046] With respect to sample Nos. 2, 9, and 10, the Young's modulus Eof the resin adhesive at 25° C. and the glass transition temperature Tgare significantly higher in comparison with other samples.

[0047] Therefore, the thermal stress 6 that affects the slider increases(refer to equation 1), resulting in a significantly high adhesivedeformation.

[0048] In order to improve the reliability of the flying height(spacing), the variation in the flying height in response to temperaturemust be suppressed within ±3 nm. Therefore, the adhesive deformation ofthe slider at each of 5° C., 25° C., and 50° C. also must be suppressedwithin ±3 nm, and a difference between the adhesive deformation of theslider at an operating temperature of 5° C. and the adhesive deformationof the slider at an operating temperature of 50° C. also must besuppressed within ±3 nm.

[0049] Sample Nos. 1, 3, 4, 5, 6, 7, and 8 in table 1 satisfy theabove-mentioned conditions.

[0050] Therefore, in view of the adhesive deformation of the slider,preferably, the resin adhesive has a Young's modulus at 25° C. of 700 to5,200 kg/cm² and a glass transition temperature Tg of 4 to 70° C.

[0051] In sample No. 3, although the adhesive deformation is suppressedto 3 nm or less, the bond strength (peel strength) is 50 gf or lesswhich is lower in comparison with other samples.

[0052] In sample No. 5, although the glass transition temperature of 4°C. is significantly low, the bond strength (peel strength) is 50 gf ormore.

[0053] That is, the major factor which determines the bond strengthpresumably lies in the Young's modulus E rather than the glasstransition temperature Tg.

[0054] In detail, at an operating temperature of 25° C., with respect tosample No. 5, although the resin adhesive is considered to havesignificantly low elasticity since the glass transition temperature is4° C., the actual resin adhesive in sample No. 5 functions as aviscoelastic body and the bond strength does not greatly decrease sincethe resin adhesive has a significantly high Young's modulus E of 1,000kg/cm² at 25° C.

[0055] On the contrary, with respect to sample No. 3, at an operatingtemperature of 25° C., although the resin adhesive is considered tofunction as a viscoelastic body and have relatively high bond strengthsince the glass transition temperature is 28° C., the actual resinadhesive in sample No. 3 has low bond strength since the resin adhesivehas a significantly low Young's modulus E of 400 kg/cm² at 25° C.

[0056] Accordingly, in table 1, preferable samples are Nos. 1, 4, 5, 6,7, and 8.

[0057] These samples have a Young's modulus E at 25° C. in the range of700 to 5,200 kg/cm² and a bond strength of 50 gf or more, which areconditions of preferred resin adhesives in the present invention.

[0058] Also, in accordance with the present invention, the glasstransition temperature Tg of the resin adhesive preferably ranges from 4to 70° C.

[0059] Next, at an operating temperature T of 25° C., a value ofE(T)×(Tg−T) represented in equation 1 was calculated with respect tosample Nos. 1, 2, 3, 4, 6, 8, 9, and 10 shown in table 1.

[0060] The results are shown in table 2. In table 2, samples are listedby sorting in an ascending order with respect to the value of E(25°C.)×(Tg−25° C.). The adhesive deformation of the slider at 25° C. isalso listed. TABLE 2 Adhesive E(25° C.) · (Tg-25° C.) deformation Sample(Logarithmic value (Crown height) (nm) No. Adhesive in parentheses) 25°C. 3 Acrylic    1,200 (3,079) 0.4 4 Acrylic    7,000 (3,845) 0.4 1 Epoxy  45,000 (4,653) 0.4 6 Acrylic   132,000 (5,121) 1.3 8 Acrylic   234,000(5,326) 2.0 9 Acrylic   392,200 (5,594) 9.8 2 Epoxy 1,444,500 (6,160)27.4 10 Cyanoacrylate 1,554,000 (6,191) 22.8

[0061] As shown in table 2, as the value of E(25° C.)×(Tg−25° C.)increases, the adhesive deformation of the slider at 25° C. increases.

[0062] As indicated in equation 1, Δα (a difference in coefficient ofthermal expansion between the slider and the flexure) is a constant, inorder to decrease a thermal stress δ, it is recommended that the valueof E(T)×(Tg−T) be decreased.

[0063] At an operating temperature of 25° C., as shown in table 2,sample Nos. 3, 4, 1, 6, and 8 can suppress the adhesive deformation to 3nm or less. In sample No. 3, as shown in table 1, the bond strength at25° C. is as low as 30 gf.

[0064] Accordingly, preferable samples in table 2 are Nos. 4, 1, 6, and8, and these samples have a value of E(25° C.)×(Tg−25° C.) in the rangeof 7,000 to 234,000 kg·°C./cm².

[0065] That is, by selecting a resin adhesive that has a value of E(25°C.)×(Tg−25° C.) in the range of 7,000 to 234,000 kg·°C./cm² at anoperating temperature of 25° C., the adhesive deformation of the slidercan be suppressed to 3 nm or less, and also, a bond strength of 50 gf ormore can be obtained.

[0066] When a conductive resin film is formed between the leading end ofthe slider and the flexure, since the conductive resin film must be aflexible adhesive the same as the resin adhesive, the conductive resinfilm must have the same properties as those of the resin adhesivedescribed above.

BRIEF DESCRIPTION OF THE DRAWINGS

[0067]FIG. 1 is a partial side view which shows a floating type magnetichead device for use in a hard disk apparatus or the like as anembodiment of the present invention;

[0068]FIG. 2 is a partial perspective view of the tip region of themagnetic head device shown in FIG. 1 taken from the reverse side; and

[0069]FIG. 3 is a side view which shows a conventional floating typemagnetic head device for use in a hard disk apparatus or the like.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0070]FIG. 1 is a partial side view which shows a floating type magnetichead device for use in a hard disk apparatus or the like and FIG. 2 is apartial perspective view of the tip region of the magnetic head deviceshown in FIG. 1 taken from the reverse side.

[0071] The magnetic head device includes a slider 1 and a support 2 forsupporting the slider 1.

[0072] The slider 1 is composed of a ceramic material and a thin-filmelement 4 is provided on the trailing end B of the slider 1. An airbearing surface (ABS) la is formed on the surface of the slider 1 facinga disk D.

[0073] The thin-film element 4 is formed by depositing a magneticmaterial such as Permalloy (an Ni—Fe alloy) and an insulating materialsuch as alumina. The thin-film element 4 includes a magnetic detectingsection for reproducing magnetically recorded signals recorded in thedisk D or a magnetic recording section for recording magnetic signals inthe disk D, or both the magnetic detecting section and the magneticrecording section. The magnetic detecting section is, for example, an MRhead including a magnetoresistive element (MR element). The magneticrecording section includes an inductive head in which a coil and a coreare formed by patterning.

[0074] The support 2 includes a load beam 5 and a flexure 6.

[0075] The load beam 5 is composed of a leaf spring material such asstainless steel. A bent section 5 a having rigidity is formed on eachside of the load beam 5 from the upper right side in FIG. 1 to thevicinity of the top. The bent section 5 extends to the substantiallymiddle position of the load beam 5, a leaf spring section (not shown inthe drawing) which does not have the bent section 5 a is formed from theend of the bent section 5 a through the base of the load beam 5.

[0076] A spherical pivot 7 which protrudes downward in the drawing isformed on the planar section sandwiched by the bent section 5 a.

[0077] The apex of the pivot 7 abuts against the upper surface of theslider 1 with a tongue 6 b of the flexure 6 therebetween.

[0078] The flexure 6 is composed of a leaf spring such as stainlesssteel. The flexure 6 includes a fixed section 6 a and the tongue 6 b,and a step 6 c connects the fixed section 6 a to the tongue 6 b.

[0079] As shown in FIG. 1, to the lower surface of the tongue 6 b, theslider 1 is bonded with a resin adhesive 8.

[0080] As shown in FIG. 2, in the tip region of the flexure 6, aconductive pattern 14 is formed from the fixed section 6 a through thetongue 6 b. The width of the conductive pattern 14 formed on the tongue6 b increases toward the base end of the flexure 6 to form a connection14 a which connects to the slider 1.

[0081] On the trailing end B of the slider 1, an electrode terminalsection 4 a formed of a thin film extracted from the thin-film element 4is provided at the same distance as that of the connection 14 a.

[0082] In the present invention, the electrode terminal section 4 aprovided on the trailing end B of the slider 1 and the connection 14 aprovided on the flexure 6 are rigidly bonded together by a joint 9formed by ball bonding using gold (Au) or the like.

[0083] The joint 9 is covered with a reinforcing resin film 10 forprotection, as shown in FIG. 1.

[0084] When the trailing end B of the slider 1 is rigidly bonded to thetongue 6 b of the flexure 6 by the joint 9 formed by ball bonding usingAu or the like as described above, since the slider 1 has a coefficientof thermal expansion which is different from that of the flexure 6, theresin adhesive (after curing) 8 for bonding the slider 1 and the tongue6 b must be a flexible adhesive which can absorb (buffer) the strain Ecaused by the difference in coefficient of thermal expansion between theslider 1 and the flexure 6 and can decrease internal stress resultingfrom curing shrinkage.

[0085] In the present invention, as the flexible resin adhesive 8, forexample, an adhesive containing a thermoplastic resin such as an acrylicresin, a polyurethane resin, a polyester resin, or a nylon resin as amajor constituent, or containing a thermosetting resin such as an epoxyresin which is flexible in the operating temperature region may beselected.

[0086] Although the method for curing the resin adhesive 8 may include areactive process such as heating or UV radiation, or a solvent dryingprocess, in the present invention, the method for curing is not limitedto any one of the above.

[0087] Next, with respect to the properties of the resin adhesive 8(after curing), in the present invention, the resin adhesive 8preferably has a Young's modulus E in the range of 700 to 5,200 kg/cm²at 25° C. and a bond strength (peel strength) of 50 gf or more.

[0088] In addition, preferably, the resin adhesive 8 has a glasstransition temperature Tg in the range of 4 to 70° C.

[0089] If the resin adhesive 8 has a Young's modulus E in the range of700 to 5,200 kg/cm² at 25° C., the adhesive deformation of the slider 1can be reduced.

[0090] Specifically, when the ABS la of the slider 1 protrudes in thedirection of the disk D and a distance between the peak of theprotrusion and the flat or crown ABS la before deformation is defined asan adhesive deformation, the adhesive deformation can be set at 3 nm orless in the range of 5 to 50° C., and a difference between the adhesivedeformation at 5° C. and the adhesive deformation at 50° C. can be setat 3 nm or less.

[0091] Accordingly, the absolute value of the variation in the flyingheight δ1 (refer to FIG. 1) in response to temperature can be suppressedto 3 nm or less, and thus, problems such as collision of the trailingend B of the slider 1 with the disk D or a decrease in output because ofan increase in the flying height δ1 as has been experienced in the pastwill not occur.

[0092] Also, preferably, at an operating temperature T of 25° C., theproduct obtained by multiplying the Young's modulus E at 25° C. by thedifference when 25° C. is subtracted from Tg (Tg−25° C.) is in the rangeof 7,000 to 234,000 kg·°C./cm² If the value E (25° C.)×(Tg−25° C.)ranges from 7,000 to 234,000 kg·°C./cm², the adhesive deformation of theslider 1 at 25° C. can be suppressed to 3 nm or less, and the bondstrength (peel strength) at 25° C. can be increased to 50 gf or more.

[0093] As shown in FIG. 1, when a fillet conductive resin film 11 isformed between the leading end A of the slider 1 and the tongue 6 b ofthe flexure 6, the conductive resin film 11 preferably has the sameproperties as those of the resin adhesive 8.

[0094] The reason for providing the conductive resin film 11 is tosecure electrical connection between the slider 1 and the flexure 6.

[0095] The magnetic head in the present invention described above isused for a CSS type hard disk apparatus (apparatus for magneticrecording and reproducing). When the disk stops, the slider 1 is pressedtoward the upper surface of the disk D by means of elastic force of theleaf spring section at the base of the load beam 5, and the ABS la ofthe slider 1 is brought into contact with the surface of the disk D.When the disk D starts to rotate, the entire slider 1 is lifted by ashort distance δ1 from the surface of the disk D because of an airflowbetween the slider 1 and the disk D. The leading end A may be liftedhigher above the disk D than the trailing end B, or the leading end Aonly may be lifted from the surface of the disk and the trailing end Bmay come into contact with the surface of the disk D continuously ordiscontinuously during rotation.

[0096] As described above, in the present invention, the flexible resinadhesive 8 (after curing) is used to bond the slider 1 and the tongue 6b of the flexure 6, a portion of the strain E between the slider 1 andthe tongue 6 b can be absorbed (buffered) by deformation of the resinadhesive 8, and the thermal stress δ that affects the slider 1 can bereduced, enabling a decrease in the adhesive deformation of the slider1.

[0097] Specifically, the resin adhesive 8 preferably has a Young'smodulus E in the range of 700 to 5,200 kg/cm² at 25° C. and a bondstrength (peel strength) of 50 gf or more. A resin adhesive 8 having theabove properties can suppress the adhesive deformation of the slider 1,to 3 nm or less.

[0098] Preferably, the resin adhesive 8 has a glass transitiontemperature Tg in the range of 4 to 70° C.

[0099] Also, in the present invention, the resin adhesive 8 preferablyhas a product obtained by multiplying the Young's modulus E at 25° C. by(Tg−25° C.) in the range of 7,000 to 234,000 kg·°C./cm².

[0100] If the value of E (25° C.)×(Tg−25° C.) is in the range of 7,000to 234,000 kg·°C./cm², the adhesive deformation of the slider 1 at 25°C. can be suppressed to 3 nm or less and the bond strength (peelstrength) at 25° C. can be increased to 50 gf or more.

[0101] As described above, in the present invention, adhesivedeformation of the slider 1 can be decreased, and specifically can besuppressed to 3 nm or less. Thus, spacing loss can be reduced, stableoutput signals are obtainable, and the minimum flying height can besecured.

[0102] As described above in detail, in the present invention, since aresin adhesive such as a thermoplastic resin which is flexible aftercuring is used in order to bond the slider and the flexure together, aportion of the strain between the slider and the flexure caused by thedifference in coefficient of thermal expansion can be absorbed bydeformation of the resin adhesive, enabling a decrease in the adhesivedeformation of the slider.

[0103] With respect to properties of the resin adhesive, in the presentinvention, the resin adhesive preferably has a Young's modulus E in therange of 700 to 5,200 kg/cm² at 25° C. and a bond strength (peelstrength) of 50 gf or more.

[0104] Also, preferably, the resin adhesive has a glass transitiontemperature Tg in the range of 4 to 70° C.

[0105] By using a resin adhesive having the properties described above,the adhesive deformation can be suppressed to 3 nm or less, and thus, astable output can be obtained and the minimum flying height can besecured.

What is claimed is:
 1. A magnetic head comprising: a slider having anyone of recording and reproducing elements; and a flexure having anelastically deformative tongue, said slider and said flexure beingbonded together with a resin adhesive therebetween, wherein, said resinadhesive has a Young's modulus E in a range of 700 to 5,200 kg/cm² at25° C. and a bond strength of 50 gf or more.
 2. A magnetic headaccording to claim 1 , wherein said resin adhesive has a glasstransition temperature Tg in a range of 4 to 70° C.
 3. A magnetic headaccording to claim 1 , wherein, at an operating temperature T of 25° C.,said resin adhesive has a product {E·(Tg−25° C.)} obtained bymultiplying the Young's modulus E at 25° C. by the difference when 25°C. is subtracted from the glass transition temperature Tg of said resinadhesive in a range of 7,000 to 234,000 kg·°C./cm².
 4. A magnetic headaccording to claim 2 , wherein, at an operating temperature T of 25° C.,said resin adhesive has a product ΔE·(Tg−25° C.)} obtained bymultiplying the Young's modulus E at 25° C. by the difference when 25°C. is subtracted from the glass transition temperature Tg of said resinadhesive in a range of 7,000 to 234,000 kg·°C./cm².
 5. A magnetic headaccording to claim 1 , wherein a conductive resin film is formed betweenan end of said slider and said flexure as a countermeasure againststatic electricity, and said conductive resin film has the sameproperties as those of said resin adhesive.
 6. A magnetic head accordingto claim 2 , wherein a conductive resin film is formed between an end ofsaid slider and said flexure as a countermeasure against staticelectricity, and said conductive resin film has the same properties asthose of said resin adhesive.
 7. A magnetic head according to claim 3 ,wherein a conductive resin film is formed between an end of said sliderand said flexure as a countermeasure against static electricity, andsaid conductive resin film has the same properties as those of saidresin adhesive.
 8. A magnetic head according to claim 4 , wherein aconductive resin film is formed between an end of said slider and saidflexure as a countermeasure against static electricity, and saidconductive resin film has the same properties as those of said resinadhesive.